Process of producing isobornyl esters.



UNITED STATES PATENT OFFICE.

OURT PHILIPP, OF DRESDEN, GERMANY, ASSIGNOR TO OHEMISOHE FABRIK VONHEYDEN AKTIENGESELLSOHAFT, OF DRESDEN, GERMANY.

PROCESS OF PRODUCING ISOBORNYL ESTERS.

Specification of Letters Patent.

Application filed May 4, 1906.

To all whom it may concern:

Be it known that I, CURT PHILIPP, a subject of the King of Saxony, andresident of Dresden, in the Kingdom of Saxony, German Empire, haveinvented a new and useful Improvement in the Manufacture of IsobornylEsters from Pinene Hydrochlorid or Pinene Hydrobromid, of which thefollowing is a specification.

It is known that by heating a solution of pinene hydrochlorid in glacialacetic acid with silver acetate for several weeks in the water bath, amixture of much camphene with a small quantity of isobornyl acetate(about 70 grams isobornylacetate from 400 grams of pinene hydrochlorid)is obtained (see Bertchte der Dewischen Chemischen Gesellschaft, Vol.32, page 2309). It is also known that, by addition of fatty acids tocamphene, with or without condensing agents, isobornyl esters are formed(see Uhegmt'schcs Centralblatt, 1902, 1, page 1219 By boiling a solutionof pinene hydrochlorid in glacial acetic acid with lead acetate,camphene is obtained, while by heating these ingredients in an autoclaveto 180 C. a mixture of bornyland isobornylacetate is obtained (seeFrench Letters Patent 349896). In working according to the improvedmethod hereinafter described, the transformation of pinene hydrochloridinto isobornyl acetate can take place at water bath temperature withoutthe use of an autoclave.

The improved method consists in heating pinene hydrochlorid with thefatty acid salts of heavy metals in an excess of fatty acids. A halogensalt of a heavy metal, for example chlorid of zinc, may also be added.Instead of the fatty acid salts of the heavy metals, the oxids orcarbonates of those metals may be employed, these being intermediatelytransformed into the said salts by the excess of the fatty acidsemployed. If fatty acid salts of zinc, iron, or copper are employed, theaddition of a halogen salt of a heavy metal is not necessary. But if thefatty acid salts of other heavy metals, 6. g. oxid of lead, areemployed, the addition of chlorid of zinc is necessary, as otherwise thereaction will take place in a different way. Probably chlorid of leadand the zinc salts of fatty acids are then formed intermediately (seeexample 7). The reaction takes place at water bath temperature and canbe considerably hastened by heating to the boiling point under reflux.

Example 1: 172 parts of pinene hydrochlorid, 500 parts of formic acid of98 to 100 per cent. strength, 45 parts of oxid of zinc, are heatedtogether using a reflux condenser. Zinc formate insoluble in the excessof the formic acid, is formed and very quickly dissolved on boiling. Theprocess is completed in a short time. The mass is oured into water, theoil floating on the surface is sepa rated off, washed with water andwith a solution of soda and distilled in cacao. The distillate consistschiefly of isobornyl for- -mate possessing the known properties.

Example 2: 172 arts of pinene hydrochlorid, 500 arts of glacial aceticacid, 45 parts of oxid of zinc, are digested for 20 hours on a boilingwater bath and then worked up according to Example 1. Isobornyl acetateossessing the known properties is obtained.

Example 3: 172 parts of pinene hydrochlorid, 300 parts of glacial aceticacid, 45 parts of oxid of zinc, are boiled for 1 to 2 hours using areflux condenser and then worked up according to Example 1. Iso bornylacetate is obtained in this case also.

Example 4: 172 parts of pinene hydrochlorid, 500 parts of isobutyricacid, 45 parts of oxid of zinc, are boiled for to 1 hour using thereflux condenser and are worked up according to Exam le 1.Isobornyl-isobutyrate having the rnown properties is obtained.

Example 5: 172 parts of pinene hydrochlorid, 500 parts of glacial aceticacid, parts of ferric oxid, are boiled for 20 hours, using the refluxcondenser, and then worked up according to Example 1. A good yield ofisobornyl acetate is obtained.

Example 6: 172 arts of pinene hydrochlorid, 500 parts of glacial aceticacid, 45 parts of oxid of copper, are boiled for 20 hours using thereflux condenser and are worked up according to Example 1. Isobornylacetate is obtained.

Example 7: 172 parts of pinene hydrochlorid, 500 arts of glacial aceticacid, 165 parts of oxid of lead, 30 parts of chlorid of zinc, are boiledfor'24 to 30 hours using the reflux condenser. The product of thereaction is recipitated with water, neutralized with so a and distilledwith steam. The dis tilled oil is separated from the water and disbornylesters consisting in heating pinene tilled in vacuo. Isobornyl acetateof the hydrochlorid with fatty acids and With fatty known properties isobtained.

Example 8: 172 parts of pinene hydrochlorid, 500 parts of glacial aceticacid, 216 described. parts of oXid of mercury, 30 parts of chlorid v Intestimony, that I claim the foregoing of zinc, are boiled for 20 hoursusing the rel as my invention, I have signed my name in flux condenserand then Worked up accordpresence of two Witnesses, this 23rd day ofGURT PHILIPP.

ing to Exam le 7. Isobornyl acetate is ob April, 1906. tained. Ad itionof chlorid of zinc is indis- 19 pensable in this case also.

What I claim is:

Process for the direct manufacture of iso- Witnesses:

PAUL E. SonrLLING, PAUL ARRAs.

l i l acid salts of heavy metals, substantially as 15

